Download A case-control study among Chinese Han population

Association between genetic variants of the leukotriene biosynthesis pathway and the risk of stroke: a
case-control study among Chinese Han population
SUN Hao+, ZHANG Jing+, WANG Jun, SUN Tao, XIAO Hang* and ZHANG Jinsong*
Keywords: leukotriene A4 hydrolase; Arachidonate 5-lipoxygenase; leukotrienes; genetics; stroke
Department of Emergency, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China (Sun H and Zhang
JS)
Department of Emergency, Wuxi People's Hospital, Wuxi 214023, China (Zhang J)
Laboratory of Neurotoxicology, School of Public Health, Nanjing Medical University, Nanjing 210029, China (Wang J and
Xiao H)
Department of Epidemiology and Biostatistics, Nanjing Medical University, Nanjing 210029, China (Sun T)
+
Equal contributors
*Correspondence to: Dr. ZHANG Jin-song, Department of Emergency, First Affiliated Hospital, Nanjing Medical University,
Nanjing 210029, China (Tel: +86 25 83718836×6529; fax: +86 25 86527613; E-mail: [email protected]); Pro. XIAO Hang,
Laboratory of Neurotoxicology, School of Public Health, Nanjing Medical University, Nanjing 210029, China (Tel: +86 25
86862956; fax: +86 25 86527613; E-mail: [email protected])
This work was supported by Natural Science Foundation of Jiangsu Province (No. H201005) and Medicial Innovation Team
Foundation of Jiangsu Province (No. LJ201122).
Background Leukotrienes are arachidonic acid derivatives long known for their inflammatory properties. Leukotriene-based
inflammation has been demonstrated to play a crucial role in atherosclerosis, a major risk factor for several human diseases.
Recently, human genetic studies from us and others suggest that single nucleotide polymorphisms (SNPs) in leukotriene
pathway genes influence the risk of atherosclerotic diseases such as stroke.
Methods To assess the role of additional leukotriene pathway genes in stroke risk within Chinese Han population, we
sequenced the promoter, exonic, and intronic regions of leukotriene A4 hydrolase (LTA4H) and Arachidonate 5-lipoxygenase
(ALOX5), and then genotyped 5 SNPs in LTA4H and 4 SNPs in ALOX5 among 691 cases with stroke and 732 controls from
Chinese.
Results We detected a significant association between an intronic SNP in LTA4H (rs6538697) and stroke in our subjects
(adjusted odds ratio (OR), recessive model, 1.75; P = 0.022); and the SNP rs2029253 in ALOX5 was associated with a
decreased risk of stroke (adjusted OR, 0.76; 95% confidence interval (CI), 0.59-0.97). Genetic parameter and association
studies were carried out with SPSS 16.0.
Conclusions To our knowledge, these results for the first time suggested that the genetic variants in LTA4H and ALOX5 might
modulate the risk of stroke in Chinese Han population.
S
understanding of the disease etiology.
incidence of stroke is high and increasing all over the world
Leukotrienes are arachidonic acid derivatives well known
and it is now a major public health burden for China.1-2
for
Many large scale epidemiological and intervention studies
inflammation has been demonstrated to play a crucial role in
have identified risk factors for stroke including smoking,
atherosclerosis.10
hypertension, diabetes, and dyslipidemia state.3-4 However,
increased inflammation within the plaque, genes involved in
the known risk factors do not fully account for the overall
the inflammatory processes are considered as good
risk of stroke. Evidence from twins, family, animal studies
candidates for assessing their association with the risk of
and human researches has consistently suggested a genetic
stroke. Indeed, recent human genetic studies11-12 including
contribution to the risk of stroke.5-8 As a complex disease, it
previous work from us13-14 suggest that single nucleotide
is believed that multiple factors or variables, including
polymorphisms (SNPs) in leukotriene pathway genes
genetic variation and environmental conditions contribute to
influence the risk of atherosclerotic diseases including
the development of stroke and studying the potential
stroke.
troke is one of the leading causes of long-term
disability and the second leading causes of death. The
interaction of these risk factors
will facilitate the
their
inflammatory properties.9
As
plaque
rupture
Leukotriene-based
correlates
with
The first enzymatic step in the leukotriene pathway is the
complications of stroke. It is still controversial whether
oxidation of arachidonic acid to leukotriene A4 (LTA4) by
ALOX5 gene polymorphisms are risk factors for stroke.
ALOX5. LTA4 is an unstable intermediate leukotriene which
is further metabolized to either leukotriene B4 (LTB4) by
The human LTA4H gene is mapped to chromosome 12q23
LTA4H or conjugated to produce a series of related cysteinyl
and consists of nineteen exons. A previous study20 reported
leukotrienes (cysLTs) - LTC4, LTD4, and LTE4. All of
that abundant expression of LTA4H correlated with plaque
these metabolites, in particular LTB4, are reported to be
instability, suggesting LTA4H as a potential target for
important mediators of various inflammatory responses and
pharmacological intervention in the treatment of human
relevant to the development of atherosclerosis.9 Several
atherosclerosis. The association between common allelic
proteins in the leukotriene pathway are detected in human15
variants (HapK) of the LTA4H gene and the risk of
and mouse16 atherosclerotic plaque. In addition, genetic
myocardial infarction and stroke were first demonstrated by
studies in mouse have demonstrated a pathological role of
DeCODE investigators in an Icelandic cohort.21 Furthermore,
the
in a separate study a variant in LTA4H gene was found to
ALOX5
pathway
(leukotriene
pathway)
in
atherosclerosis.17
confer a 1.5-fold increase in risk of small vessel disease with
replication in a United Kingdom stroke cohort.22 However,
The human ALOX5 gene is mapped to chromosome 10q11.2
these findings have not been broadly and convincingly
and consists of fourteen exons. In 2004, one study18 reported
replicated. In particular, the information about the genetic
that carotid intima media thickness was increased in patients
contribution of LTA4H to stroke in Chinese population is
with two copies of the non-wild type alleles of a tandem SP1
still lacking.
binding motif at the promoter of ALOX5 compared to
patients who had two copies of the wild type allele.
Based on previous findings, this study was aimed to
Increased dietary arachidonic acid significantly enhanced the
determine the association between stroke and SNPs in the
influence of atherogenic genotype, while increased dietary
two implicated candidate genes in the leukotriene pathway.
intake of eicosapentaenoic acid (EPA) plus docosahexaenoic
We selected 9 SNPs (4 in ALOX5 and 5 in LTA4H) from the
acid (DHA) decreased the effect. Despite the various
HapMap data for Chinese (http://www.hapmap.org/) and
evidences linking the ALOX5 pathway to atherosclerosis and
carried out a case-control association study to investigate the
its well-established involvement in chronic inflammatory
association between common genetic variants across ALOX5
conditions such as asthma and coronary artery disease
and LTA4H sequence and the risk of stroke and its subtypes
(CAD),12,19 few human genetic studies have confirmed an
among a Chinese Han population.
association between ALOX5 polymorphisms and clinical
Revision (ICD-10), the diagnosis of stroke was based on the
outcomes of strict neurological examination-computed
METHODS
tomography (CT), magnatic resonance imaging (MRI), or
This study aimed to assess the risk factors of stroke and was
sponsored by the JiangSu province. Informed consent was
obtained from each subject (or their next of kin) who
donated 5 ml of blood used for DNA extraction. The overall
research protocol was reviewed and approved by the
Institutional Review Boards of Nanjing Medical University.
both. Controls were selected from 2 groups. One consisted
of inpatients (52%) with slight illnesses from the
otorhinolaryngology, gastroenterology, and orthopedics. The
other group was recruited from patients undergoing annual
medical examination (48%) who were free of neurological
diseases with the same exclusion criteria as the cases.
Controls were from the same demographic area (Eastern
All subjects were recruited between November 2008 and
May 2010 at the Brain Hospital Affiliated to Nanjing
China) and frequency-matched to the cases by age and
gender.
Medical University (Nanjing) and First Affiliated Hospital
of Nanjing Medical University (Nanjing) with a response
rate of 91.8% (1423/1550). On account of our hospital-based
case-control study, a total of 691 hospitalized patients who
were genetically-unrelated ethnic Han Chinese from Eastern
China (JiangSu province and surrounding regions) were
recruited.
In
accordance
to
the
methods
described
previously,13 we only recruited patients with 1 of 3 subtypes
of atherosclerotic stroke: lacunar infarction (lacunar),
cerebral
thrombosis
(thrombosis),
and
In addition to neurological history and family history of
cerebrovascular disease (CVD), coronary artery disease
(CAD), hypertension and DM, some other vascular risk
factors for each sample were also noted including body mass
index (BMI), alcohol consumption, cigarette smoking,
systolic
and
diastolic
blood
pressure,
total
plasma
cholesterol (TC), triglycerides (TG), blood glucose level and
high-density lipoprotein (HDL) cholesterol.
intracerebral
hemorrhage (hemorrhage). Cases who had other subtypes of
stroke (transient ischemic attack, cerebral embolism,
Diagnostic criteria
subarachnoid hemorrhage and cerebrovascular malformation)
Hypertension was defined as a mean of 3 independent
were not included in our study. Severe systemic diseases
measures of blood pressure ≥140/90 mmHg whether taking
such as collagenosis, endocrine and metabolic disease
antihypertensive drugs or not (in line with the diagnostic
(except for diabetes mellitus, DM), general inflammation,
criteria of China Guideline of Hypertension Updated 2005).
neoplastic and renal diseases were also excluded. According
DM
to the International Classification of Diseases, Tenth
hyperglycemia and was diagnosed by any one of the
was
characterized
by
recurrent
or
persistent
following diagnostic criteria: (1) random plasma glucose
(EOCAD).11,23 For LTA4H, we selected 3 additional SNPs
≥11.1 mmol/L, (2) plasma glucose ≥11.1 mmol/L at 2 hours
(rs2660845, rs6538697 and rs1978331) with minor alleles
after a 75 g oral glucose challenge, (3) fasting plasma
frequency >5% in Chinese from haplotype HapK which
glucose ≥7.0 mmol/L (in line with the diagnostic criteria of
were defined by DeCODE groups.20
World Health Organization 1999). Cigarette smoking was
defined as average consumption of ≥1 cigarettes per day for
As a result, 9 SNPs were selected (5 SNPs in ALOX5 and 4
more than one year. Former smokers with more than five
SNPs in LTA4H). The primary information of the genotyped
years smoking cessation are not included. Alcohol
SNPs in LTA4H and ALOX5 genes were shown in Table 1.
consumption was defined as alcohol consumption of ≥50 ml
The selected 9 SNPs were genotyped in all 1423 subjects by
for at least 1 time per week for more than 3 months22.
polymerase chain reaction–restriction fragment length
Family history was defined as any self-reported history in
polymorphism (PCR-RFLP) assay. Genomic DNA was
first-degree relatives (parents, siblings, or children).
extracted from the peripheral white blood cells using the
phenol/chloroform method. The information of primers and
SNPs selection and genotyping
restriction
SNPs were selected in two ways. First, two SNPs in ALOX5
Massachusetts, USA) are listed in Table 2. Genotyping was
(rs2228064 and rs7913948) were selected according to
performed independently by two researchers in a blinded
genotype data obtained from unrelated Beijing Han Chinese
way. About 10% of the samples were selected randomly for
in the HapMap database (Data sources: HapMap Data Rel
repeated genotyping to ensure that the results were 100%
24/Phase II, Nov08, on NCBI B36 assembly, dbSNP b126)
concordant.
enzymes
used
(New
England
BioLabs,
based on pairwise r2 (>0.8) among all common SNPs with
minor allele frequency (MAF) >0.05 within a 75.93 kb
Statistical analysis
region spanning the whole ALOX5 gene (including 2 kb
Statistic analysis was performed using the SPSS 16.0
upstream and 2 kb downstream, intron region was excluded)
package for windows (SPSS Inc, Chicago, USA). A P-value
using the pairwise option of the Haploview 4.0 software.
<0.05
Two SNPs in LTA4H (rs2660899 and rs2540487) were also
continuous clinical variants were compared by unpaired
selected in the same way. In addition, we attempted to
Student’s t test. Chi-square test was used to analyze the
genotype two intronic SNPs in ALOX5 (rs2029253 and
categorical clinical variants and evaluate the differences in
rs3740107) which were investigated in previous studies and
frequency distributions of each allele and genotype of the
associated with atherosclerotic diseases such as coronary
ALOX5 and LTA4H polymorphisms between the cases and
artery disease (CAD) and early onset coronary artery disease
controls. We used conditional univariate and multivariate
(two-tailed)
was
considered
significant.
The
logistic regression model to analyze the crude and adjusted
odds ratios (ORs) (adjusted for age, gender, body mass
index, and past history of CAD, hypertension and DM) for
the risk of stroke and the 95% confidence intervals (CIs).
Hardy–Weinberg equilibrium of the genotype distribution of
the controls was assessed by a goodness-of-fit Chi-square
test.
Individual SNP association analysis
The SNP IDs, locations and allele frequencies are shown in
Table 1. We identified 5 polymorphisms in LTA4H gene and
4 polymorphisms in ALOX5 gene (see Methods). For all
genotypes, distributions in controls were consistent with the
Hardy–Weinberg equilibrium model (P>0.05). None of the 9
SNPs showed significant difference in allele frequencies
between cases and controls.
RESULTS
Basic characteristics of subjects
Table 3 summarizes the baseline characteristics of the 691
cases and 732 controls in this study. Briefly, the mean age
was 66.28±10.50 years for cases and 65.51±8.94 years for
controls; 61.8% cases and 64.9% controls were male. The
difference in the distribution of age (P=0.131) and gender
(P=0.226) between cases and controls was not statistically
We calculated the P-value and OR for the dominant and
recessive model, but found no strong evidence of dominant
effects. Therefore, we only presented the recessive model for
all SNPs in the table. We observed that two SNPs,
rs6538697 (P=0.022) in LTA4H and rs2029253 (P=0.030) in
ALOX5, showed a significant difference in the point estimate
and the variance of the Ors between cases and controls.
significant.
Multivariate logistic regression analysis revealed that when
As expected, the prevalence of most common risk factors of
atherosclerosis was significantly higher in cases than in
controls. Cases had a higher prevalence of risk factors for
vascular diseases, including high BMI, family history of
CVD, history of CAD, hypertension and DM, high blood
pressure, high levels of glucose, TG, TC and low levels of
stratification analyses were performed according to the
gender, age, BMI, CAD history, hypertension history and
DM history, homozygotic type CC genotype for rs6538697
in LTA4H gene had an increased risk of stroke (adjusted OR,
1.75; 95% CI, 1.09-2.82), compared to the wild type TT and
heterozygous type TC (Table 4).
HDL cholesterol (P<0.05). However, smoking, alcohol
intake, family history of CAD, hypertension and diabetes
were not statistically significant between the two groups
(P>0.05).
In contrast, for rs2029253 in ALOX5 gene, multivariate
logistic regression analysis revealed that GG genotype had a
decreased risk of stroke (adjusted OR, 0.76; 95% CI,
0.59-0.97), comparing to the wild type AA and heterozygous
type AG (Table 4). After fully adjusted, rs2029253 GG
are likely candidates of stroke-associated genes and that
genotype showed a significant protective effect.
their variants might therefore modulate the susceptibility to
stroke.
DISCUSSION
ALOX5 and LTA4H are important genes in the leukotriene
In this study, we selected 5 SNPs in the ALOX5 gene and 4
SNPs in the LTA4H gene and investigated their associations
with the risk of stroke. To the best of our knowledge, this is
the first study that investigates such association in a Chinese
Han population. We found that the rs6538697 SNP in
ALOX5 was associated with a significantly increased risk of
stroke, while the rs2029253 in LTA4H was shown to have a
significant protective effect.
biosynthesis pathway. Recently the close relationship
between polymorphisms in the leukotriene biosynthesis
pathway and atherosclerosis was reported10-12. In addition,
ALOX5 and LTA4H have been shown to affect the risk of
atherosclerotic diseases including CAD, a finding now
confirmed in Caucasian20, African 23 and Asian27 populations.
In contrast, evidence for the association of genetic
polymorphisms in the leukotriene biosynthesis pathway and
the risk of stroke are still very limited.
Although most genetic effects exert relatively weak
influences in multifactor diseases such as stroke, the
population attributable risk is still significant due to the high
disease-associated mortality and morbidity in China.
stroke (adjusted OR=0.76, P=0.030). This is in contrary to
development of atherosclerosis, including the formation of
atherosclerotic lesions and the subsequent progression to
mature
promotes
atheroma.
Moreover,
thrombosis,
a
inflammatory
dreadful
response
complication
of
atherosclerosis and major risk factor for stroke. The
Leukotriene biosynthesis pathway has recently drawn much
attention for its potential role in atherosclerosis-related
traits.9 A number of biochemical,26 genetic,9 epidemiological
and pharmacological
provided
evidence
10
studies over the past few years have
for
the
pro-atherogenic
role
the rs2029253 SNP in ALOX5 gene and decreased risk of
24-25
Inflammation has emerged as a key contributor in the
8
In the present study, we found a significant association of
the findings by Yoshida T et al,27 which demonstrated that
subjects carrying the high-risk allele at rs2029253 had a
higher frequency for CAD in East Asians (OR=1.84,
P=0.003). The inconsistency is likely due to the different
samples size (35 in Yoshida T et al. versus over 691 in this
study) and statistical power. Another potential reason is
regional disparity (East Asia versus East China). Moreover
we found that a SNP in LTA4H gene, rs6538697, was
significantly associated with increased risk of stroke
(OR=1.62).
of
leukotrienes, suggesting that leukotriene metabolism genes
Consistent with previous reports, we did not find any SNP in
the coding sequence which leads to amino acid substitution.
stroke in Chinese Han population by potentially modulating
It is possible that the polymorphism in the intronic region is
atherosclerosis. This is the first time to confirm the
in linkage disequilibrium with unidentified variants in
association between these two genes and stroke incidence in
regulatory elements which can affect the transcriptional rate
Chinese. Leukotriene biosynthesis pathway should be
and/or expression efficiency of the two genes under
considered for valuation in future studies of genetic variation
inflammatory conditions. Another hypothesis is that intronic
in stroke. Finally, functional studies are warranted to
SNP influences the nucleotide splicing and the formation of
confirm our findings in this study.
different spliceosomes, which might change the structure of
ACKNOWLEDGMENT
the genes and interfere with protein folding.28
We sincerely thank Chunye Luan, Xiaolei Gu and Shuang
Several limitations of our study need to be addressed. First,
Lou for their assistance in recruiting the subjects.
the present study provided data on an overall assessment of
stroke risk without detailed classification of stroke
CONFLICTS OF INTEREST
phenotypes. Future studies with larger sample size may
No benefits in any form have been received or will be
specify the role of the two genes in different stroke subtypes.
received from a commercial party related directly or
Second, since the cases and controls were recruited from
indirectly to the subject of this article.
hospital, there was a potential selection bias. Further
large-scale randomized long-term studies are warranted to
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Table 1. Primary information on genotyped SNPs of the LTA4H and ALOX5 gene in cases and controls
Gene/SNP
No.
SNP ID
Genomic
position
*
Genetic
MAF
position
Database
†
Controls
Cases
P‡
P for
HWE §
LTA4H
1
rs2660899
96430420
5' near gene
0.422
0.490
0.496
0.751
0.074
2
rs2540487
96429783
5' near gene
0.189
0.196
0.174
0.125
0.463
3
rs2660845
96438553
5' near gene
0.467
0.429
0.420
0.644
0.844
4
rs6538697
96403610
Intron 14
0.367
0.256
0.276
0.238
0.534
5
rs1978331
96409201
Intron 11
0.422
0.382
0.350
0.345
0.386
6
rs2228064
45878050
ThrThr in exon 2
0.089
0.054
0.062
0.346
0.995
7
rs7913948
45868889
5' near gene
0.178
0.178
0.190
0.382
0.294
8
rs2029253
45891484
Intron 3
0.433
0.390
0.392
0.521
0.870
9
rs3740107
45923770
Intron 6
0.239
0.212
0.235
0.146
0.961
ALOX5
*
SNP position in NCBI dbSNP (http://www.ncbi.nlm.nih.gov/projects/SNP/).
†
Minor allele frequency for Chinese in HapMap.
‡
P value for allele distribution difference between cases and controls.
§
HWE (Hardy-Weinberg equilibrium) P value in the control group.
Table 2. Primary information for the SNPs of the LTA4H and ALOX5 gene
Gene/SNP
No.
SNP ID
Base
change
Restriction
Primer sequence (5'-3') *
Tanneal (℃)
F:GAAGGAATGAATAGAAGGAATACTC (T→C)A
55.9
HpyF3I
57
Psp1406I
58.2
Bsh1236I
58.2
Acc65I
58.2
MspI
55.2
Hin1I
64
TaqI
57
Hin6I
55.2
Tru1I
enzymes
LTA4H
1
rs2660899
G>T
R: CCTCTGGTTAATGACTAGCCAG
2
rs2540487
G>A
F: AACAATTACTGTGCCTCCCCGT
R: AAACGTAGAAAAGGCCTATCAGAAC(G→C)G
3
rs2660845
A>G
F: TTCATAGTGTCTACCACTGGCCCC
R: TCAAGGAAGGGCAAGAGAGTGC
4
rs6538697
T>C
F: TCTCCGTAAATCATGCTTGCTA(T→A)GTAC
R: ACGGAGTCCCAGTCACAACTCT
5
rs1978331
C>T
F: AAAGCGTCTTTACTGTGTAGCA
R: AAACTACCTTACATAGAACAGTGAC(A→C)C
ALOX5
6
rs2228064
G>A
F: ACCTGAAGTACATCACGCTGAAGAC
R: TCCATCCCTCAGGACAACCTC
7
rs7913948
A>G
8
rs2029253
A>G
F: GAAGCCGCCCAGGAGCGCT(G→T)C
R: CACATCTGGACATGCGGGGCTG
F: TTCCACAGTGTATGGCCTGG(T→G)C
R: ACTCTCCTCTCCATCTCTTGTCTGGA
9
rs3740107
A>G
F: TTTCACCTAACCTCTTTCTTCTTAT(G→T)T
R: TAAGATGAAGGAATGGCAGC
*
Underline represents the mismatched base using a primer-introduced restriction analysis-PCR method.
Table 3. General clinical characteristics of the stroke cases and controls
Controls (n =732)
Variables
N
Age (years)
Cases (n =691)
%
65.51±8.94
N
%
66.28±10.50
P*
0.131
Sex
Male
Female
2
Body mass index (kg/m )
475
64.9
427
61.8
257
35.1
264
38.2
23.27±2.38
24.03±3.07
0.226
0.000
Smoking status
Never
541
73.9
524
75.8
Ever
191
26.1
167
24.2
0.403
Never
591
80.7
572
82.8
Ever
141
19.3
119
17.2
High salt diet
74
10.1
63
9.1
0.526
High fat diet
42
5.7
54
7.8
0.118
High glucose diet
43
5.9
24
3.5
0.033
CAD
41
5.6
38
5.5
0.933
CVD
38
5.2
68
9.8
0.001
Hypertension
146
19.9
161
23.3
0.124
Diabetes
74
10.1
51
7.4
0.069
CAD
18
2.5
100
14.5
0.000
Hypertension
218
29.8
528
76.4
0.000
Diabetes
94
12.9
202
29.2
0.000
Drinking status
0.319
Eating habit
Family history
Past history
Blood pressure (mmHg)
Systolic
125.44±17.68
145.11±24.23
0.000
Diastolic
79.21±30.75
86.05±24.23
0.000
BG
5.55±2.18
6.64±2.66
0.000
TC
4.51±0.98
4.68±1.21
0.003
TG
1.28±0.72
1.71±1.20
0.000
HDL-C
1.27±0.28
1.17±0.35
0.000
6.63±2.72
7.91±4.04
0.000
62.26±11.55
67.20±12.89
0.000
Biochemical indicator
Routine
WBC
NE,%
*
Two-sided  test for the frequency distribution of selected variables between cases and control.

Table 4. Logistic regression analysis of associations between genotypes of the SNPs and stroke risk
GENE/SNP
No.
SNP ID
Genotype
rs2660899
Controls
Cases
P
*
OR (95% CI) *
P
value
Adjusted
†
(95% CI)
OR
†
N
(%)
N
(%)
value
GG/GT
568
77.6
544
78.7
——
——
——
——
TT
164
22.4
147
21.3
0.606
0.94(0.73,1.20)
0.981
1.00(0.75,1.34)
GG/GA
707
96.6
677
98.0
——
——
——
——
AA
25
3.4
14
2.0
0.112
0.59(0.30,1.14)
0.167
0.59(0.28,1.25)
AA/AG
492
67.2
462
66.9
——
——
——
——
GG
240
32.8
229
33.1
0.887
0.98(0.79,1.23)
0.992
1.00(0.78,1.29)
TT/TC
692
94.5
632
91.5
——
——
——
——
CC
40
5.5
59
8.5
0.024
1.62(1.07,2.45)
0.022
1.75(1.09,2.82)
CC/CT
461
63.0
425
61.5
——
——
——
——
TT
271
37.0
266
38.5
0.567
1.07(0.86,1.32)
0.126
1.21(0.95,1.56)
GG/GA
730
99.3
689
99.3
——
——
——
——
AA
2
0.3
2
0.3
0.954
1.06(0.15,7.54)
0.882
1.19(0.12,11.44)
AA/AG
232
31.7
237
34.3
——
——
——
——
GG
500
68.3
454
65.7
0.296
0.89(0.71,1.11)
0.634
0.94(0.73,1.21)
AA/AG
450
61.5
467
67.6
——
——
——
——
GG
282
38.5
224
32.4
0.016
0.77(0.62,0.95)
0.030
0.76(0.59,0.97)
AA/AG
270
36.9
285
41.2
——
——
——
——
GG
462
63.1
406
58.8
0.092
0.83(0.67,1.03)
0.436
0.91(0.71,1.16)
LTA4H
1
2
3
4
5
rs2540487
rs2660845
rs6538697
rs1978331
ALOX5
6
7
8
9
rs2228064
rs7913948
rs2029253
rs3740107
*
Genotype frequencies in cases and controls were compared using a 2 test.
†
Adjusted for age, gender, body mass index, and past history of CAD, hypertension and DM.